MIDI in/out clock sync

[Sanderr303]

Enhancement Summary

MIDI in and/or out clock sync to use LMMS together with a hardware or software sequencer.

Implementation Details / Mockup

Within in the MIDI setting be able to select midi clock in and/or out sync.

Please search the issue tracker for existing feature requests before submitting your own.

• I have searched all existing issues and confirmed that this is not a duplicate.

[firewall1110]

ExternalSync API (will fix issue #523 JACK transport support with ExSync API draft)

is planned to be base for this

P.S.
Post only to connect my PR with this issue

[Sanderr303]

Thanks a lot for pointing me to that topic.